کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1165097 1491063 2013 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Bismuth-dispersed xerogel-based composite films for trace Pb(II) and Cd(II) voltammetric determination
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Bismuth-dispersed xerogel-based composite films for trace Pb(II) and Cd(II) voltammetric determination
چکیده انگلیسی

We report for the first time the synthesis of bismuth-modified (3-mercaptopropyl) trimethoxysilane (MPTMS) and its application for the determination of lead and cadmium by anodic stripping voltammetry. Xerogels made from bismuth-modified MPTMS and mixtures of it with tetraethoxysilane, under basic conditions (NH3·H2O), were characterized with scanning electron microscopy, energy dispersive spectroscopy, infrared spectroscopy and electrochemical methods. Bismuth-modified xerogels were mixed with 1.5% (v/v) Nafion in ethanol and applied on glassy carbon electrodes. During the electrolytic reductive deposition step, the bismuth compound on the electrode surface was reduced to metallic bismuth. The target metal cations were simultaneously reduced to the respective metals and were preconcentrated on the electrode surface by forming an alloy with bismuth. Then, an anodic voltammetric scan was applied in which the metals were oxidized and stripped back into the solution; the voltammogram was recorded and the stripping peak heights were related to the concentration of Cd(II) and Pb(II) ions in the sample. Various key parameters were investigated in detail and optimized. The effect of potential interferences was also examined. Under optimum conditions and for preconcentration period of 4 min, the 3σ limit of detection was 1.3 μg L−1 for Pb(II) and 0.37 μg L−1 for Cd(II), while the reproducibility of the method was 4.2% for lead (n = 5, 10.36 μg L−1 Pb(II)) and 3.9% for cadmium (n = 5, 5.62 μg L−1 Cd(II)). Finally, the sensors were applied to the determination of Cd(II) and Pb(II) ions in water samples.

Figure optionsDownload as PowerPoint slideHighlights
► A novel bismuth precursor, Bi-dispersed MPTMS xerogel, is proposed.
► EDS analysis showed an excellent distribution of Bi atoms in the material.
► Bi-xerogel/Nafion composite film-modified GC electrodes exhibit low LODs.
► Sensors were applied to the rapid screening of Cd(II) and Pb(II) in water samples.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Analytica Chimica Acta - Volume 769, 26 March 2013, Pages 49–55
نویسندگان
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